The cleansing of industrial exhaust gases using wet electrostatic scrubbers techniques is well-known. Such apparatus uses fine water spray droplets or cascading sheets of water in place of the conventional solid collector plates of an electrostatic precipitator. The interaction of a finely atomized water spray uniformly charged to one polarity, with an oppositely charged aerosol, creates a combined spray scrubber and collector apparatus wherein charged particles are physically captured by the water droplets or cascading sheet of water enhanced by the attraction of the charged particles toward the oppositely charged spray droplets or sheet of water. Following Coulomb's Law, the small particles are attracted toward and captured by the water droplets or sheet. Such apparatus is shown in U.S. Pat. Nos. 2,357,354 and 2,357,355, wherein an electrostatic dust precipitator utilizing liquid spray is disclosed. U.S. Pat. No. 3,331,192 discloses an electrostatic precipitator apparatus of the liquid spray type in which aerosol particles are charged to one polarity, liquid spray droplets are oppositely charged and the gas stream carrying the aerosol is contacted with the liquid spray droplets. As a result, the particulate matter migrates to the liquid spray droplets and is collected. In this device the contact between the liquid spray and the aerosol-containing gas stream is carried out in a large open container.
The well-known processes noted above, while permitting removal of relatively larger particles from a gas stream have too small and inefficient a contact between the aerosol particulate matter in the gas stream and the droplets to remove the relatively smaller particles to the extent necessary to meet current air pollution standards. This invention provides additional improvements in the contaminated aerosol charging apparatus, the liquid spray charging apparatus, the method and apparatus for contacting the charged particulate material and the oppositely charged liquid, and in the arrangement of all these improved components to create a more efficient and commercially feasible wet electrostatic scrubber and collector of aerosol particles.